我有一个指向迭代器元组的zip迭代器。我想用一个函子提供thrust :: transform,它将使用元组来抓取元素并产生一个标量输出。采用迭代器元组并产生基本类型的一元函数
我的程序不工作,我不知道为什么。
我认为这可能与某些事情有关: CUDA thrust zip_iterator tuple transform_reduce,但更改仿函数的模板参数并没有成功。
下面的代码编译:
#include <iostream>
#include <thrust/transform.h>
#include <thrust/functional.h>
#include <thrust/device_vector.h>
#include <thrust/device_ptr.h>
#include <thrust/iterator/zip_iterator.h>
#include <thrust/tuple.h>
typedef thrust::device_vector<double>::iterator realIter;
typedef thrust::tuple<realIter,realIter> Tup;
typedef thrust::zip_iterator<Tup> Zip;
typedef thrust::tuple<double,double> Tup2; //I tried replacing Tup with this in the functor
struct dummyOp : public thrust::unary_function<Tup, double> {
__host__ __device__ double operator()(Tup &tup){
double result = *thrust::get<0>(tup);
return result;
}
};
int main(){
thrust::device_vector<double> A(4);
thrust::device_vector<double> B(4);
thrust::device_vector<double> C(4);
A[0] = 1.; A[1] = 2.;
A[2] = 3.; A[3] = 4.;
B[0] = 4.; B[1] = 3.;
B[2] = 2.; B[3] = 1.;
Tup tup = thrust::tuple<realIter,realIter>(A.begin(),B.begin());
Zip zippy = thrust::zip_iterator<Tup>(tup);
dummyOp f;
// The following does not work:
//thrust::transform(zippy, zippy + 4, C.begin(), f);
std::cout << "A:\n";
thrust::copy(A.begin(), A.end(), std::ostream_iterator<double>(std::cout, " "));
std::cout << "\nB:\n";
thrust::copy(B.begin(), B.end(), std::ostream_iterator<double>(std::cout, " "));
std::cout << "\nC:\n";
thrust::copy(C.begin(), C.end(), std::ostream_iterator<double>(std::cout, " "));
std::cout << std::endl;
std::cout <<"get<0>(zippy[0]) returns:\n" << thrust::get<0>(zippy[0]) << std::endl;
std::cout <<"get<1>(zippy[1]) returns:\n" << thrust::get<1>(zippy[1]) << std::endl;
return 0;
}
并运行它给:
$ ./so2
A:
1 2 3 4
B:
4 3 2 1
C:
0 0 0 0
get<0>(zippy[0]) returns:
1
get<1>(zippy[1]) returns:
3
随着问题的行注释掉,我们有:
$ nvcc -arch=compute_35 so2.cu -o so2
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/detail/internal_functional.h(322): error: function "dummyOp::operator()" cannot be called with the given argument list
argument types are: (thrust::detail::tuple_of_iterator_references<double &, double &, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>)
object type is: dummyOp
detected during:
instantiation of "thrust::detail::enable_if_non_const_reference_or_tuple_of_iterator_references<thrust::tuple_element<1, Tuple>::type>::type thrust::detail::unary_transform_functor<UnaryFunction>::operator()(Tuple) [with UnaryFunction=dummyOp, Tuple=thrust::detail::tuple_of_iterator_references<thrust::detail::tuple_of_iterator_references<double &, double &, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, double &, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>]"
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/detail/function.h(60): here
instantiation of "Result thrust::detail::wrapped_function<Function, Result>::operator()(const Argument &) const [with Function=thrust::detail::unary_transform_functor<dummyOp>, Result=void, Argument=thrust::detail::tuple_of_iterator_references<thrust::detail::tuple_of_iterator_references<thrust::device_reference<double>, thrust::device_reference<double>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>, thrust::device_reference<double>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>]"
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/cuda/detail/for_each.inl(57): here
instantiation of "void thrust::system::cuda::detail::for_each_n_detail::for_each_kernel::operator()(thrust::system::cuda::detail::bulk_::parallel_group<thrust::system::cuda::detail::bulk_::concurrent_group<thrust::system::cuda::detail::bulk_::agent<1UL>, 0UL>, 0UL> &, Iterator, Function, Size) [with Iterator=thrust::zip_iterator<thrust::tuple<Zip, thrust::detail::normal_iterator<thrust::device_ptr<double>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, Function=thrust::detail::wrapped_function<thrust::detail::unary_transform_functor<dummyOp>, void>, Size=unsigned int]"
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/cuda/detail/bulk/detail/apply_from_tuple.hpp(71): here
instantiation of "void thrust::system::cuda::detail::bulk_::detail::apply_from_tuple(Function, const thrust::tuple<Arg1, Arg2, Arg3, Arg4, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type> &) [with Function=thrust::system::cuda::detail::for_each_n_detail::for_each_kernel, Arg1=thrust::system::cuda::detail::bulk_::parallel_group<thrust::system::cuda::detail::bulk_::concurrent_group<thrust::system::cuda::detail::bulk_::agent<1UL>, 0UL>, 0UL> &, Arg2=thrust::zip_iterator<thrust::tuple<Zip, thrust::detail::normal_iterator<thrust::device_ptr<double>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, Arg3=thrust::detail::wrapped_function<thrust::detail::unary_transform_functor<dummyOp>, void>, Arg4=unsigned int]"
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/cuda/detail/bulk/detail/closure.hpp(50): here
instantiation of "void thrust::system::cuda::detail::bulk_::detail::closure<Function, Tuple>::operator()() [with Function=thrust::system::cuda::detail::for_each_n_detail::for_each_kernel, Tuple=thrust::tuple<thrust::system::cuda::detail::bulk_::parallel_group<thrust::system::cuda::detail::bulk_::concurrent_group<thrust::system::cuda::detail::bulk_::agent<1UL>, 0UL>, 0UL> &, thrust::zip_iterator<thrust::tuple<Zip, thrust::detail::normal_iterator<thrust::device_ptr<double>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, thrust::detail::wrapped_function<thrust::detail::unary_transform_functor<dummyOp>, void>, unsigned int, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>]"
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/cuda/detail/bulk/detail/cuda_task.hpp(58): here
[ 9 instantiation contexts not shown ]
instantiation of "RandomAccessIterator thrust::system::cuda::detail::for_each(thrust::system::cuda::detail::execution_policy<DerivedPolicy> &, RandomAccessIterator, RandomAccessIterator, UnaryFunction) [with DerivedPolicy=thrust::system::cuda::detail::tag, RandomAccessIterator=thrust::zip_iterator<thrust::tuple<Zip, thrust::detail::normal_iterator<thrust::device_ptr<double>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, UnaryFunction=thrust::detail::unary_transform_functor<dummyOp>]"
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/detail/for_each.inl(44): here
instantiation of "InputIterator thrust::for_each(const thrust::detail::execution_policy_base<DerivedPolicy> &, InputIterator, InputIterator, UnaryFunction) [with DerivedPolicy=thrust::system::cuda::detail::tag, InputIterator=thrust::zip_iterator<thrust::tuple<Zip, thrust::detail::normal_iterator<thrust::device_ptr<double>>, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type, thrust::null_type>>, UnaryFunction=thrust::detail::unary_transform_functor<dummyOp>]"
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/system/detail/generic/transform.inl(57): here
instantiation of "OutputIterator thrust::system::detail::generic::transform(thrust::execution_policy<DerivedPolicy> &, InputIterator, InputIterator, OutputIterator, UnaryFunction) [with DerivedPolicy=thrust::system::cuda::detail::tag, InputIterator=Zip, OutputIterator=thrust::detail::normal_iterator<thrust::device_ptr<double>>, UnaryFunction=dummyOp]"
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/detail/transform.inl(44): here
instantiation of "OutputIterator thrust::transform(const thrust::detail::execution_policy_base<DerivedPolicy> &, InputIterator, InputIterator, OutputIterator, UnaryFunction) [with DerivedPolicy=thrust::system::cuda::detail::tag, InputIterator=Zip, OutputIterator=thrust::detail::normal_iterator<thrust::device_ptr<double>>, UnaryFunction=dummyOp]"
/usr/local/cuda/bin/../targets/x86_64-linux/include/thrust/detail/transform.inl(142): here
instantiation of "OutputIterator thrust::transform(InputIterator, InputIterator, OutputIterator, UnaryFunction) [with InputIterator=Zip, OutputIterator=thrust::detail::normal_iterator<thrust::device_ptr<double>>, UnaryFunction=dummyOp]"
so2.cu(36): here
更新: 虽然我还是真的很想帮助理解上面的代码中的问题,下面的工作:
struct dummyOp {
template <typename Tuple>
__host__ __device__ double operator()(Tuple tup){
double result = thrust::get<0>(tup);
return result;
}
};
的想法是从这里被盗:https://github.com/thrust/thrust/blob/master/examples/arbitrary_transformation.cu
这并不构成回答我自己的问题,因为我还是不明白什么是错的原始代码中的类型。
另外:它不能使参数成为明确的参考(Tuple &)。这是否意味着tup通过价值传递?